The present invention relates generally to a power-driven cutting apparatus for cutting material such as sheet metal, and more particularly to a cutting apparatus which can be configured for use in connection with a sheet slitter, including an adjustable cutter mechanism for facilitating use with materials having varying thicknesses.
During processing of sheet materials such as sheet metal, it is frequently necessary to subdivide rolls or pieces of sheet stock into narrower rolls or pieces. A slitter apparatus is typically employed for this purpose, with the apparatus including a plurality of cutting mechanisms which cut the sheet stock lengthwise to the desired narrower widths.
Attendant to slitting of sheet material in this fashion, it is common for opposite edge portions of the sheet stock to be cut, and recycled as scrap material. Because such pieces of scrap material have lengths corresponding to that of the original sheet stock, it is desirable to continuously cut the scrap edge portions as the slitter apparatus is operated to slit the sheet stock.
The present invention is directed to a cutter apparatus which is particularly suited for use in association with a sheet stock slitter, wherein the cutting apparatus of the present invention includes an adjustable cutter mechanism to facilitate handling of varying thicknesses of sheet material.
A cutting apparatus embodying the principles of the present invention is rotatably driven for use with an associated slitter apparatus, with the apparatus including cooperating knife assemblies to cut scrap edge portions of sheet stock as it is cut lengthwise by the slitter apparatus. The knife assemblies include opposed, opposite-hand, helical-like cutting knives, with counter-rotation of the knife assemblies moving respective ones of the knives into cutting cooperation with each other. The cutting edges of the opposing knives are offset, allowing a piece of material pinched therebetween to be sheared as the cutting edges converged toward each other as the knife assemblies are counter-rotated. Notably, the present apparatus includes an arrangement for axially offsetting one of the knife assemblies relative to the other, thereby acting to adjust the offset (i.e., horizontal knife clearance) between opposing ones of the knives. By this arrangement, the gap or clearance between the knives can be readily and efficiently selectively adjusted, thus promoting efficient cutting of scrap sheet material of varying thicknesses. In accordance with the illustrated embodiment, the cutting apparatus includes first and second pairs of knife assemblies, with the apparatus positioned in operative association with a sheet slitter, such that respective pairs of the knife assemblies cut the opposite edge scrap portions of sheet material as it is slit.
As disclosed herein, the present cutting apparatus includes a frame, and a pair of shafts rotatably mounted on the frame. The shafts are geared to each other for counter-rotation when one of the shafts is rotatably driven.
A pair of cooperating knife assemblies are respectively mounted on the shafts for counter-rotation therewith. Each of the knife assemblies includes a hub mounted on the respective one of the shafts, and at least one knife blade, so that counter-rotation of the shafts moves respective ones of the knife blades of the pair of knife assemblies into cutting cooperation with each other. In a current embodiment, each knife assembly includes four cutting blades evenly spaced (at 90 degrees) about the rotational axis of the knife assembly.
As noted, the present invention includes an adjustment mechanism for moving a movable one of the knife assemblies axially of the respective one of the shafts of the apparatus, to thereby alter the clearance between the cooperating knife blades. In order to provide adjustment in this manner, the one of the shafts on which the movable knife blade is axially movable is hollow, with the adjustment mechanism of the apparatus including an inner shaft positioned within the hollow shaft. The inner shaft is connected to the movable knife assembly, with the inner shaft being movable axially for axially moving the movable knife assembly.
The adjustment mechanism of the present invention further includes a motor-driven screw jack mounted on the apparatus frame, with the screw jack connected to the inner shaft of the adjustment mechanism for selectively reciprocably moving the inner shaft. A bearing housing connected to the screw jack operatively interconnects the screw jack with the reciprocably movable inner shaft, with the bearing housing having a pair of thrust bearings for reciprocably moving the inner shaft, while permitting rotation of the inner shaft relative to the bearing housing.
In the illustrated embodiment, the present cutting apparatus includes first and second pairs of cooperating knife assemblies, each of which is configured to include a movable knife assembly, and its own adjustment mechanism for adjustably positioning the movable one of the knife assemblies. Efficient operation of an associated sheet slitter apparatus is thus promoted, with each pair of adjustable knife assemblies acting to continuously cut the opposite edge scrap portions of sheet material as the material is slit lengthwise.
Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.